A special legendary weapon received for completing Survival challenges. As expected, it's very powerful, with guaranteed multiple legendary effects. As expected, it's only available in Survival mode.
Survival mode reward, available June 25 - July 1: Perform Covert Operations:
Kill a creature while using a Stealth Boy
Destroy a Turret while sneaking
Hack a terminal at night
Pick a lock at night
Take a camera picture of a humanlike creature at night
Strategy
The easiest place to complete this challenge is at Berkeley Springs: It spawns ghouls and scorched for taking pictures and killing with a Stealth Boy, while the town hall includes three turrets on its perimeter, a hackable terminal on the ground floor, and a locked door on the top floor. Stealth Boys can be found at the Pleasant Valley Ski Resort, spawning at the front desk (baggage intake) and on the desk in the back office near the stairwell leading to the vendor bot.